The CEO of Colossal Order, Mariina Hallikainen just made it pretty clear that there will be an announcement of some kind next week on GDC 2017. My rock solid guess is that it will be the announcement of “Expansion 4”. We’ll see next week!
Read the CO word of the week here: https://forum.paradoxplaza.com/forum/index.php?threads/co-word-of-the-week-5-8-2017.1001403/
Maybe also familiarise yourself with the rumours going around the Expansion 4: https://colossalnews.wordpress.com/2017/01/20/expansion-4-reveal-date-and-core-focus-announced/